The units of Omega Galaxy fought Draconis Combine Mustered Soldiery troops on Schuyler and Meilen and then faced off against Clan Nova Cat forces on Yamarovka. The Tenth Cuirassiers landed on Yamarovka hoping to destroy the last of the Alshain Avengers units, but the Nova Cat's Zeta Galaxy beat them to the punch. When Zeta Galaxy departed the world before even offering token resistance to the Tenth Cuirassiers, the enraged Cuirassiers responded by hitting several Nova Cat worlds. By employing tactics used by Inner Sphere forces rather than zellbrigen, the Tenth rapidly took several worlds from the Nova Cats in a series of swift but brutal battles.[1]

Having been formed and trained specifically to fight Inner Sphere opponents, Omega was ideally suited for fighting the Word of Blake. As a consequence Omega saw some of the heaviest fighting of the Jihad, working alongside the Ghost Bear Alpha Galaxy throughout the conflict. The first campaign Omega was involved in was the assault on Luthien;[2] in December 3074, the Alpha, Omega and Rho Galaxies of Clan Ghost Bear swept onto Luthien, intent on wiping out all Blakist forces.[3][4][5][6][7] Omega expected to face Blakist forces but instead found itself attacked by the Sixth Benjamin and Fortieth Dieron Regulars, regiments loyal to the Kokuryu-kai or Black Dragon Society. Although Omega Galaxy devastated both rebel formations, Galaxy Commander Ortiz had to compensate for her malcontent warriors, who wanted to concentrate on the Blakist forces.[8]

The Ghost Bear forces on Luthien never once offered zellbrigen to any of the Word units and effectively eradicated the Word forces on Luthien by the 20th of December. Very few survivors from the Word of Blake managed to flee or become captives, and the Ghost Bear forces destroyed any DCMS forces that attempted to interfere in the Ghost Bear campaign against the Word.[9][10] As suddenly as they had arrived, the Ghost Bear forces left Luthien at the end of January, leaving the DCMS to frantically redeploy forces to fortify the world; the relief units began arriving two weeks later on the 14th of February, only to find no sign of any Blakist troops in the wake of the Ghost Bear withdrawal.[10][11] The destruction of the Forty-second Shadow Division on Luthien at the hands of the three galaxies of Ghost Bear troops represented the first instance of a Shadow Division being destroyed completely.[12]

After Luthien Omega Galaxy formed a part of the Ghost Bear campaign designated as Alpha Wave, continuing to operate alongside Alpha Galaxy.[2] In late August 3075 Alpha Wave launched a campaign to liberate Kaus Borealis, again ignoring all hails from Draconis Combine forces. In mid-September the allied coalition leader Devlin Stone travelled to Kaus Borealis with a small diplomatic party to meet with Clan Ghost Bear and attempt to enlist their support for the coalition. On the 21st of September, the Ghost Bears agreed to assist the coalition, and soon launched another wave of attacks against nearby worlds occupied by the Blakists.[13][14]

After landing on Dyev alongside Alpha and Pi Galaxies[17] during a wave of attacks against worlds in the Word of Blake Protectorate in July 3076,[18][19] Omega Galaxy found itself facing a Blakist counteroffensive in December when a task force breached the blockade of Ghost Bear and Snow Raven ships in orbit and landed six Divisions of troops on the surface of Dyev. The Blakists landed around Trogport and the planetary capital, Novaya Mensk, before deploying outwards. Omega Galaxy found itself fighting alongside Alpha Galaxy against the Twenty-eighth Militia Division and the Third Bryant and First Lipton Protectorate Militia Divisions; the Blakists used the Tupik Chasm and various mining tunnel complexes that connected to the chasm as fortifications to try and resist the Ghost Bear attack.[13]

In 3077, Alpha,[20]Beta,[16] Rho[7] and Omega Galaxies launched an attack on Dieron.[2] Dieron was a bloodbath for all the Ghost Bear Galaxies involved; when they landed on Dieron Omega had already been reduced to approximately half strength from fighting on Dyev and Khan Kabrinski initially held them back as a reserve unit, but Omega was involved in a horrific firefight around the Ghost Bear's main drop zone; Omega managed to hold off multiple Protectorate Militia units for a week despite their lack of numbers. Once Alpha reinforced Omega the Protectorate forces were destroyed. Unfortunately the conflict devastated Omega Galaxy, with only two Clusters surviving the campaign. They were integrated into Beta to make up losses in that formation.[21]

The two surviving Clusters from Omega, the Fifth Bear Guards and the 357th Assault Cluster, were seperated back out from Beta Galaxy when Beta returned to the Dominion and used to reform Omega, with each contributing units to form the new Galaxy Command Trinary, although that left each Cluster severely understrength.[2]

In the years between 3079 and 3085 Omega Galaxy underwent further rebuilding efforts, with mixed results. Whereas Omega had been regarded with suspicion by the rest of the Ghost Bear touman after it had originally been formed - despite having been formed from the best warriors available - the bulk of the replacement personnel assigned to Omega as it rebuilt were Rasalhagian recruits who lacked a firm grounding in the Way of Clans. Whereas Omega had always walked a tightrope in the past between the ways of honor and the dishonorable excesses of the Inner Sphere, the balance was considered to have firmly shifted towards the latter, with many Ghost Bears coming to shun Omega for what was considered to be a descent into dezgra.[22]

The Dominion attempted to check this downward slide; after the Jihad the Dominion disbanded three Galaxies - Omicron, Pi and Sigma Galaxies, and the surviving personnel from one of the Clusters within Pi Galaxy, the Twenty-third Provisional Garrison Cluster, were assigned to units across Omega, while the Third Bear Regulars were transferred in as a discrete unit from Theta Galaxy. It was hoped that the combination of these Clan warriors plus those originally assigned to Omega Galaxy would provide a good example for the Galaxy. Unfortunately, both the Third and Twenty-third had been primarily defensive Clusters, and the transition into a front-line formation was difficult for them; as a result, Omega was moved to locations where the nearest significant enemy force was unlikely to launch an attack - the nearest enemy force being Kappa Galaxy of Clan Wolf - while also placing Omega under the watchful eye of the Dominion's Tau Galaxy.[22]

In 3136 Omega Galaxy found itself on a relief mission to aid the planet Vega.[23]

Omega Galaxy were directly involved in the formation of the Vega Protectorate during the widespread invasions of the Republic of the Sphere. While the Vega Protectorate was independent Omega was starved of supplies by the Rasalhague Dominion, and the little new equipment it was able to obtain consisted largely of salvage or equipment purchased from Clan Sea Fox. When the First Vega Regulars successfully fought off an invasion by the Twelfth Falcon Jaegers in 3142 they not only achieved a notable victory - they also secured valuable salvage.[24]

Whilst Omega lacked equipment, it had no problem attracting recruits from amongst the Vegan population, particularly after the Dominion began shipping Freeminders into the Protectorate. Omega's supply lines improved after the Vega Protectorate was absorbed into the Dominion and became a semi-autonomous province; access to the Dominion brought access to cast-off equipment from other Dominion forces. By 3145 the older Omega Clusters resembled frontline Clan forces once more, while the Vega Regulars were able to draw on supplies ranging from equipment dating back to the Jihad or the Second Combine-Dominion War, as well as battle armor and 'Mechs from the Watch. With the Regulars able to incorporate real 'Mechs and light battlesuits, augmenting the capabilities already offered by their tanks and infantry equipped with Clan technology, Omega Galaxy had rebuilt to the point that it could be expected to hold the worlds it was stationed across.[24]

In the fighting on Vega, Omega Galaxy is not subject to Clan honor rules when facing an Inner Sphere opponent. Inner Sphere forces may never Force the Initiative against Omega. Any bonuses an Inner Sphere unit gains by fighting a Clan foe are cancelled. However the members of Omega Galaxy are seen as tainted by other Clan forces, so any Clan force that includes Omega receives a -2 penalty to initiative rolls.[31]